This invention relates to sliding drawer suspensions for drawers for filing cabinets and the like and more especially to three-part suspensions permitting full extension of the drawer, and having an intermediate rail and two other rails for attachment to the drawer and to the cabinet, respectively. For convenience of description, said two other rails will be referred to as the inner and outer rails. The suspension also includes linear ball-bearings interposed between the outer rail and the intermediate rail and between the intermediate rail and the inner rail.
In known suspensions, all three rails have been formed as sturdy structural members of relatively large width, and this increases the costs of the materials required for fabricating the structure. In known arrangements, it has also been common to yoke two intermediate rails on opposite sides of the drawer together, or to employ friction wheels or disks journalled on the intermediate rail and frictionally engaging tracks on the outer rail and inner rail respectively, whereby the movements of the two intermediate rails on opposite sides of the drawer are synchronized, so that problems of grinding wear of the ball-bearings resulting from random movements of the intermediate rails are reduced. These expedients add to the complexity and costs of the suspension, and the friction wheels or disks are liable to slippage and wear.